Following a day in Dubbo, the pair will travel to Melbourne and back to Sydney for the Invictus Games - a Paralympics style event for defence veterans - which begin on October 20.

On October 22 the royals will spend a day on Fraser Island, before making their way to Fiji and Tonga and then back to Sydney on October 26 to close out the Games the next day.

The tour will end with four days in New Zealand.

Prime Minister Scott Morrison says he is looking forward to welcoming The Duke and Duchess of Sussex.

"Their visit will be an opportunity to promote the incredible achievements of Invictus athletes from around the world, and showcase Australian programmes promoting youth leadership, environmental and conservation efforts," he said in a statement on Monday.